The Penn State University’s Department of Nutritional Sciences has published a new study correlating children’s brain activity and response to food with obesity. The researchers scanned children’s brain activity while they viewed pictures of high- and low-calorie foods, and determined that both lean body mass and body fat are linked to how kids’ brains respond to food.

The research participants consisted of 38 children aged 7 to 10 and their parents, who participated in five total laboratory visits. Children’s body composition was measured to get lean body weight and body fat and their brain response was measured by functional magnetic resonance imaging (fMRI) scan when they looked at pictures of foods that differed in energy content.

“We think that kids with more lean body weight might have a greater reward response to higher calorie foods, in part because they have greater energy needs compared to children with less lean body weight. Lean body weight largely determines how many calories we burn each day through our resting metabolic rate. Bigger kids burn more calories, and our results show that their brains respond differently to foods,” said Nicole Fearnbach Doctoral Student Department of Nutritional Sciences, The Pennsylvania State University.

“Interestingly, we also found that children with more body fat had a reduced brain response to lower calorie foods, which tend to be the healthier options,” Fearnbach said. “It might be that kids with higher body fat find those healthier foods to be less rewarding. But we don’t know yet whether having more body fat is a cause or a consequence of these brain responses.”

The scientists discovered that neural activation in a brain region called the substantia nigra, (involved in reward, learning, and motor control) differed in children of different weight groups. Children with greater lean body weight had more powerful brain response in the substantia nigra when looking at high-calorie foods compared to children with lower lean body weight. The study also found that children with higher body fat had lower activity in this same brain area when they saw pictures of healthier, low-calorie foods like fruits, vegetables, and grilled chicken.